The invention relates to a spinning device for producing a yarn by means of a circulating air flow and, more particularly, comprising a hollow spinning cone arranged in a spinning housing and rotatably mounted about a central longitudinal axis, and a nozzle block which can be loaded with compressed air to generate the circulating air flow.
Air spinning devices for producing textile yarns are known in various embodiments and described in the patent literature.
German Patent Publication DE 40 36 119 C2 describes an air spinning device, for example, in which a fiber yarn drawn in an upstream drafting arrangement is introduced through a nozzle block into an air spinning device and arrives via a fiber band guide, which also acts as a twist stop in the inlet opening of a spinning spindle which rotates during the spinning process and is acted upon via a drive belt. On entry of the fiber band into the rotating spinning spindle, the free fiber ends are looped by means of a circulating air flow around the conical spindle head of the spinning spindle and, while the yarn is being drawn into the spindle, wind spirally around the so-called core fibers. Thus, the core fibers, together with the so-called winding fibers, form a new yarn.
The drawback in this known air spinning device, however, is that the device is relatively maintenance-intensive due to its rotatably mounted, driven spinning spindle.
A comparable device for producing a yarn by means of a circulating air flow is known from German Patent Publication DE 199 26 492 A1. In this air spinning device, the fiber band to be spun is also introduced via a fiber band guide and a nozzle block into the air spinning device and arrives in the inlet opening of a stationarily arranged hollow spinning cone. In other words, the spinning cone of this known air spinning device is not rotatably mounted, but rigidly connected to the housing of the air spinning device. As already mentioned above in conjunction with German Patent Publication DE 40 36 119 C2, the fiber band is subjected to a circulating air flow in the region of the inlet opening of the spinning cone, which air flow places the free fiber ends of the fiber band around the head of the spinning cone. When the fiber yarn is subsequently drawn into the hollow spinning cone the free fiber ends also loop spirally, as so-called winding fibers, around the core fibers and thus form a yarn.
Air spinning devices according to German Patent Publication DE 199 26 492 A1 are distinguished above all by a relatively simple design construction and are relatively low in maintenance. However, it has been shown that in the case of air spinning devices of this type with a fixed spinning cone, even though it is made of a very wear-resistant material, preferably an industrial ceramics material, there is the risk of traces of wear occurring over time in certain areas of the head of the spinning cone and these have negative effects on the functioning capacity of the device.